//
// XYPoint.cc
// Implementation of the 2D Point class
// 

#include <stdlib.h>
#include <math.h>
#include "XYpoint.h"
using namespace std;

// local counter used to produce globally unique point ID's
static int counter = 0;

// Constructor with no elements
XYPoint::XYPoint(void) : _x(0), _y(0) {
  _num = counter++;
}

// Constructor with initial x and y values
XYPoint::XYPoint(double x, double y) : _x(x), _y(y) {
  _num = counter++;
}

double XYPoint::distance(const XYPoint *other) const {
  double dx = x() - other->x();
  double dy = y() - other->y();
  return sqrt(dx * dx + dy * dy);
}

bool XYPoint::isLeftOf(const XYPoint *other) const { 
  return (_x < other->_x || (_x == other->_x && _num < other->_num));
}

bool XYPoint::isBelow(const XYPoint *other) const {
  return (_y < other->_y || (_y == other->_y && _num < other->_num));
}

ostream &operator<< (ostream &os, const XYPoint &point) {
  os << '(' << point.x() << ',' << point.y() << ')';
  return os;
}

ostream &operator<< (ostream &os, const XYPoint *point) {
  if (point == NULL) {
      os << "NULL";
  } else {
    os << *point;
  }
  return os;
}